Extended thromboprophylaxis in hospitalised patients with cancer does not reduced the rate of venous thromboembolic (VTE) events and is associated with increased risk of haemorrhage, a systematic review has found.
While the use of extended (28-42 days) thromboprophylaxis after hospitalisation has previously been shown to have benefit over standard-duration (14 days) thromboprophylaxis, this was not the case for patients with cancer, according to the review published in Blood Advances.
The systematic review and meta-analysis of the literature analysed outcomes for cancer subgroups enrolled in randomised controlled trials evaluating extended thromboprophylaxis with enoxaparin, betrixaban, or rivaroxaban.
The authors identified four RCT reporting outcomes of extended thromboprophylaxis in 3655 medically ill patients with active or history of cancer.
Patients received either extended-duration prophylaxis using enoxaparin, betrixaban, or rivaroxaban (n=1,832) or standard-duration prophylaxis using enoxaparin monotherapy (n=1,853).
The rates of VTE events were similar between the extended-duration and standard-duration groups (odds ratio [OR], 0.85).
Hospitalised patients who received extended-duration thromboprophylaxis had a higher risk of clinically relevant bleeding (OR=2.11; 95% CI 1.33-3.35).
However there was no significant risk of major bleeding (OR=1.98; 95% CI 0.62-6.35) or clinically relevant nonmajor bleeding (OR=1.85; 95% CI 0.87-3.92).
Similar results were seen after excluding a study that did not include patients with active cancer: there were no differences in total VTEs between the groups (OR=0.86) but extended thromboprophylaxis was associated with a significant increase in clinically relevant bleeding (OR=2.21).
In patients without cancer the use of extended thromboprophylaxis was associated with significant reduction in the risk of VTE (OR=0.72), but no similar association was found in those with cancer. There was a higher risk of clinically relevant bleeding in patients with and without cancer who received extended thromboprophylaxis.
The study authors said patients with cancer had higher risks of bleeding and thrombosis, making clinical decisions around pharmacologic thromboprophylaxis particularly challenging.
“On the basis of this meta-analysis, it seems that extended thromboprophylaxis increases major bleeding without reducing symptomatic VTE following hospitalization in patients with cancer,” they wrote.
Co-author Dr Jeffrey Zwicker, of the Division of Hemostasis and Thrombosis, Beth Israel Deaconess Medical Center, and Harvard Medical School, said that consistent with the guidance regarding the hospitalised noncancer population, the results argued against routine extended-duration thromboprophylaxis in patients with active or history of malignancy.
“Based on these research data, which suggest that extended prophylaxis is associated with a stronger signal for increased hemorrhage relative to thrombosis reduction, I would not advocate for routine extended prophylaxis following hospitalization for patients with cancer,” he said.
“Whether a more targeted approach based on individual assessment of bleeding versus thrombosis risk factors would alter the risk-benefit profile is not yet known,” Dr. Zwicker added.